The influence of various factors on the 3D printing performance of cement-based materials was analyzed by geometric morphology

At present, the evaluation method of 3D printing concrete constructability is not uniform. Different from the traditional analysis method, this experiment combines the geometric morphology method to analyze the influence of various factors on the 3D printing of cement-based materials. The research shows that with the increase of Mekralon, setting accelerator, and HPMC, the extrusion time becomes longer, and with the increase of nano-silica, the extrusion time becomes shorter. Nano-silica and setting accelerator can shorten the initial setting time, while HPMC and Mekralon prolong the initial setting time. The addition of HPMC can reduce the deformation of the specimen. The variation of the first layer, the second layer, and the third layer are generally consistent, and the different coefficient of the third layer is greater than that of the second layer, while the different coefficient of the first layer is the smallest. HPMC, fiber, and nano-silica can control deformation. With the increase of nano-silica and Mekralon content, flexural strength increases. With the increase of HPMC content, the flexural strength gradually decreases. Nano-silica has a good improvement effect on the flexural strength of cement-based 3D printing specimens. Geometric morphology can better characterize the properties of cement-based materials.